Transport across cell membrane

Question 1

What does selectively permeable mean?

Answer 1

Allows small, soluble molecules to pass through

Question 2

What does the Cell membrane consist of?

Answer 2

Phospholipids and Proteins

Question 3

What is Diffusion?

Answer 3

The movement of molecules, down a concentration gradient from a higher to a lower concentration

Question 4

Examples of passive transport

Answer 4

Diffusion and Osmosis

Question 5

Why is diffusion important to cells?

Answer 5

It is the way oxygen, glucose and amino acids enter cells, and the way carbon dioxide and other waste products leave the cell

Question 6

What is active transport?

Answer 6

It requires energy, for membrane proteins to act as a pump. These proteins move molecules and ions against the concentration gradient

Question 6

What is osmosis?

Answer 6

The movement of water molecules from a higher water concentration to a lower water concentration through a selectively permeable membrane

Question 7

What happens when an animal cell is placed in pure water?

Answer 7

Burst

Question 8

What happens when an animal cell is placed in a concentrated sugar/salt solution?

Answer 8

Shrink

Question 9

What happens to a plant cell when placed in pure water?

Answer 9

Become turgid, the vacuole gets larger, and the cell wall is pushed slightly outwards

Question 10

What happens to a plant cell when placed in a concentrated sugar/salt solution?

Answer 10

Becomes plasmolysed, the vacuole gets smaller, and the cell membrane pulls away from the cell wall